The use of scattered light methods for measuring the concentration of particles in exhaust gases and other colloids are believed to be in the related art.
A measuring device provided for this usually includes a fast light source, such as a laser, which radiates light into a measuring chamber through which the colloid to be measured is conducted. The measuring chamber has at least one light sensor assigned to it which detects light, that has been scattered by the particulates present in the colloid. In order to check the proper functioning of such a measuring device and to calibrate the measuring device, it is necessary to set a specified state in the measuring chamber at which the incident light is scattered in a defined and known manner. Measuring devices, that are used for official measurements, are covered by official calibration duty, whereby the necessity for supplying accurate measurement results with high reliability increases even further. Such a measuring unit is discussed in German Patent Application 10 2010 002 423.6.